Nvalence_modification

smact/__init__.py

@@ -81,6 +81,8 @@ class Element:
 
         Element.num_valence (int): Number of valence electrons
 
+        Element.num_valence_modified (int): Number of valence electrons based on a modified definition
+
 
 
     Raises:
@@ -162,6 +164,12 @@ def __init__(
             MeltingT = None
             num_valence = None
 
+        valence_data = data_loader.lookup_element_valence_data(symbol)
+        if valence_data:
+            num_valence_modified = valence_data["NValence"]
+        else:
+            num_valence_modified = None
+
         for attribute, value in (
             ("coord_envs", coord_envs),
             ("covalent_radius", dataset["r_cov"]),
@@ -200,6 +208,7 @@ def __init__(
             ("AtomicWeight", AtomicWeight),
             ("MeltingT", MeltingT),
             ("num_valence", num_valence),
+            ("num_valence_modified", num_valence_modified),
             # ('vdw_radius', dataset['RVdW']),
         ):
             setattr(self, attribute, value)

smact/data/element_valence_modified.csv

@@ -0,0 +1,98 @@
+element,NValence
+H,1
+He,2
+Li,1
+Be,2
+B,3
+C,4
+N,5
+O,6
+F,7
+Ne,8
+Na,1
+Mg,2
+Al,3
+Si,4
+P,5
+S,6
+Cl,7
+Ar,8
+K,1
+Ca,2
+Sc,3
+Ti,4
+V,5
+Cr,6
+Mn,7
+Fe,8
+Co,9
+Ni,10
+Cu,11
+Zn,12
+Ga,3
+Ge,4
+As,5
+Se,6
+Br,7
+Kr,8
+Rb,1
+Sr,2
+Y,3
+Zr,4
+Nb,5
+Mo,6
+Tc,7
+Ru,8
+Rh,9
+Pd,10
+Ag,11
+Cd,12
+In,3
+Sn,4
+Sb,5
+Te,6
+I,7
+Xe,8
+Cs,1
+Ba,2
+La,3
+Ce,4
+Pr,5
+Nd,6
+Pm,7
+Sm,8
+Eu,9
+Gd,10
+Tb,11
+Dy,12
+Ho,13
+Er,14
+Tm,15
+Yb,16
+Lu,3
+Hf,4
+Ta,5
+W,6
+Re,7
+Os,8
+Ir,9
+Pt,10
+Au,11
+Hg,12
+Tl,3
+Pb,4
+Bi,5
+Po,6
+At,7
+Rn,8
+Fr,1
+Ra,2
+Ac,3
+Th,4
+Pa,5
+U,6
+Np,7
+Pu,8
+Am,9
+Cm,10
+Bk,11

smact/data_loader.py

@@ -904,3 +904,54 @@
             )
 
         return None
+
+
+_element_valence_data = None
+
+
+def lookup_element_valence_data(symbol: str, copy: bool = True):
+    """
+    Retrieve valence electron data.
+
+    For d-block elements, the s and d electrons contribute to NValence.
+    For p-block elements, the s and p electrons contribute to NValence.
+    For s- and f-block elements, NValence is calculated from the Noble Gas electron configuration
+        i.e.
+
+    Args:
+        symbol : the atomic symbol of the element to look up.
+        copy: if True (default), return a copy of the data dictionary,
+        rather than a reference to a cached object -- only use
+        copy=False in performance-sensitive code and where you are
+        certain the dictionary will not be modified!
+
+    Returns:
+        NValence (int): the number of valence electrons
+        Returns None if the element was not found among the external
+        data.
+    """
+
+    global _element_valence_data
+
+    if _element_valence_data is None:
+        _element_valence_data = {}
+
+        df = pd.read_csv(
+            os.path.join(data_directory, "element_valence_modified.csv")
+        )
+        for _index, row in df.iterrows():
+            key = row.iloc[0]
+
+            dataset = {"NValence": int(row.iloc[1])}
+            _element_valence_data[key] = dataset
+
+    if symbol in _element_valence_data:
+        return _element_valence_data[symbol]
+    else:
+        if _print_warnings:
+            print(
+                "WARNING: Valence data for element {} not "
+                "found.".format(symbol)
+            )
+
+        return None